The present invention relates to a device and method for creating hydrodynamic cavitation in fluids, and particularly, to a device and method for creating and controlling hydrodynamic cavitation in fluids wherein the position of structural components which create cavitation and the structural components themselves are easily variable.
One of the most promising courses for further technological development in chemical, pharmaceutical, cosmetic, refining, food products, and many other areas relates to the production of emulsions and dispersions having the smallest possible particle sizes with the maximum size uniformity. Moreover, during the creation of new products and formulations, the challenge often involves the production of two, three, or more complex components in disperse systems containing particle sizes at the submicron level. Given the ever-increasing requirements placed on the quality of dispersing, traditional methods of dispersion that have been used for decades in technological processes have reached their limits. Attempts to overcome these limits using these traditional technologies are often not effective, and at times not possible.
Hydrodynamic cavitation is widely known as a method used to obtain free disperse systems, particularly lyosols, diluted suspensions, and emulsions. Such free disperse systems are fluidic systems wherein dispersed phase particles have no contacts, participate in random beat motion, and freely move by gravity. Such dispersion and emulsification effects are accomplished within the fluid flow due to cavitation effects produced by a change in geometry of the fluid flow.
Hydrodynamic cavitation is the formation of cavities and cavitation bubbles filled with a vapor-gas mixture inside the fluid flow or at the boundary of the baffle body resulting from a local pressure drop in the fluid. If during the process of movement of the fluid the pressure at some point decreases to a magnitude under which the fluid reaches a boiling point for this pressure, then a great number of vapor-filled cavities and bubbles are formed. Insofar as the vapor-filled bubbles and cavities move together with the fluid flow, these bubbles and cavities may move into an elevated pressure zone. Where these bubbles and cavities enter a zone having increased pressure, vapor condensation takes place withing the cavities and bubbles, almost instantaneously, causing the cavities and bubbles to collapse, creating very large pressure impulses. The magnitude of the pressure impulses within the collapsing cavities and bubbles may reach 150,000 psi. The result of these high-pressure implosions is the formation of shock waves that emanate from the point of each collapsed bubble. Such high-impact loads result in the breakup of any medium found near the collapsing bubbles.
A dispersion process takes place when, during cavitation, the collapse of a cavitation bubble near the boundary of the phase separation of a solid particle suspended in a liquid results in the breakup of the suspension particle. An emulsification and homogenization process takes place when, during cavitation, the collapse of a cavitation bubble near the boundary of the phase separation of a liquid suspended or mixed with another liquid results in the breakup of drops of the disperse phase. Thus, the use of kinetic energy from collapsing cavitation bubbles and cavities, produced by hydrodynamic means, can be used for various mixing, emulsyfying, homogenizing, and dispersing processes.
Devices are known in the art which utilize the passage of a hydrodynamic flow through a cylindrical flow-through chamber internally accommodating a baffle body installed across and confronting the direction of hydrodynamic flow to produce varied cavitation effects. The baffle element provides a local contraction of the flow as the fluid flow confronts the baffle element thus increasing the fluid flow pressure. As the fluid flow passes the baffle element, the fluid flow enters a zone of decreased pressure downstream of the baffle element thereby creating a hydrodynamic cavitation field.
Once such prior art device is described in U.S. Pat. No. 5,492,654 issued on Feb. 20, 1996 to the Applicant herein and other named inventors and is hereby incorporated by reference herein. The cavitation device of the ""654 Patent identifies the art as utilizing a cylindrical flow-through chamber internally accommodating a plurality of baffles elements, wherein the upstream baffle elements have a larger diameter than the downstream baffle elements. Such a device is utilized in an attempt to create and control hydrodynamic cavitation in fluids wherein the position of the baffle elements is variable. However, there is an ever-increasing need to create and control hydrodynamic cavitation to a greater degree.
This invention relates to a device and method for creating and controlling the qualitative and quantitative effects of hydrodynamic cavitation. This method and device can find application in areas such as oil processing, petroleum chemistry, and organic and inorganic synthesis chemistry among other areas. Particularly, this device is useful where the effects of cavitation would be beneficial.
This invention provides a device and method for creating hydrodynamic cavitation in fluids comprising a flow-through chamber intermediate an inlet opening and an outlet opening; a flow-through chamber having an upstream opening portion communicating with the inlet opening and a downstream opening portion communicating with the outlet opening; the cross-sectional area of the downstream opening portion of the flow-through chamber being greater than the cross-sectional area of the upstream opening portion of the flow-through chamber; and a cavitation generator located within the flow-through chamber for generating a hydrodynamic cavitation field downstream from the generator.
In the preferred embodiment, the flow-through chamber assumes the shape of a truncated cone wherein the smaller diameter cross-section of the cone (the truncated end) is locate upstream in the device.
This invention also provides at least one baffle element movable within the flow-through chamber thereby effecting the fluid flow pressure at the baffle element to produce controlled cavitation.
This invention also provides a device for creating hydrodynamic cavitation in fluids wherein the walls of the flow-through chamber are removably mounted within the device and are interchangeable with replacement walls having various shapes and configurations thereby enabling the flow-through chamber to assume various shapes and configurations to affect cavitation.
This invention further provides a device for creating hydrodynamic cavitation in fluids wherein the baffle elements of the flow-through chamber are removably mounted within the flow-through chamber and are interchangeable with replacement baffle elements having various shapes and configurations thereby affecting cavitation. In the preferred embodiment, the device utilizes conically-shaped baffle elements. However, given that the baffle elements are removable, the device can utilize baffle elements having variously shaped surfaces and configurations to affect cavitation.
Still other benefits and advantages of the invention will become apparent to those skilled in the art upon reading and understanding this disclosure.